1. Field of the Invention
The present invention relates to a construction of a liquid crystal display device, more particularly, relates to a liquid crystal display device which incorporates or can incorporate an edge light type of a backlight.
2. Description of the Related Art
In a prior liquid crystal display, a printed circuit board or a tape carrier having a circuit and the like which drives a liquid crystal panel is fixed on an electrode portion of a liquid crystal display panel.
Further, a liquid crystal display itself does not emit a light, but display a pattern and the like by controlling a transmittance or a reflectance of a light. Therefore, the liquid crystal display has a characteristic in which a display is hard to be seen unless an illuminating apparatus is installed in a dark circumference.
FIG. 6 shows a sectional view of a prior liquid crystal display disclosed in Japanese Patent Application Laying Open (KOKAI) No. 2-52313. In FIG. 6, the prior liquid crystal display device comprises a liquid crystal display panel 1, a driving LSI (IC) 2 for driving the liquid crystal display panel 1, a tape carrier 3, a backlight 4, and a circuit board 5. The prior liquid crystal display has the liquid crystal display panel 1 in a light emitting surface side of the backlight 4, and has the circuit board 5 in a rear surface side thereof. Then, they are connected to each other to the tape carrier 3 fitted with the driving IC 2.
The liquid crystal display panel 1 is a display panel in which a liquid crystal is put between electrodes. An incident/reflective light is changed by applying a voltage to the electrodes.
The driving LSI (IC) 2 is an integrated circuit in which a circuit outputting a driving signal to the liquid crystal display panel 1 is integrated, and the integrated circuit is disposed on the tape carrier 3.
The tape carrier 3 is a thin type of a flexible printed circuit board having a conductive pattern, and transmits the driving signal to the liquid crystal display panel 1.
The backlight 4 emits a light from the rear surface side thereof to the liquid crystal display panel 1, and is disposed between the circuit board 5 and the liquid crystal display panel 1.
The circuit board 5 is equipped with a signal circuit for actuating the driving LSI 2.
The tape carrier 3 disposed between the liquid crystal display panel 1 and the circuit board 5 is bonded to an electrode portion of the liquid crystal display panel 1, and also fixed on the circuit board 5 by means of a soldering.
For example, in the prior liquid crystal display device shown in FIG. 6, a thicker transparent flat plate than a lamp as a light source is generally used for a light guide plate, in a case where an edge light type of a backlight is used. In this case, a thickness of the liquid crystal display device as a whole is inevitably a total thickness of respective thicknesses of the light guide plate 4 for the backlight, the liquid crystal display panel 1 and the circuit board 5. As a result, it is difficult to make the liquid crystal display device thin. Further, there is a possibility that the LSI receives a light leaked from the edge of the light guide plate, performs an abnormal operation and carries out an erroneous liquid crystal displaying.